mpc5632m Freescale Semiconductor, Inc, mpc5632m Datasheet - Page 55

• Manufacturer Part Number: mpc5632m
• Description: Mpc5634m Microcontroller Data Sheet
• Manufacturer: Freescale Semiconductor, Inc

3.2.1
An estimation of the chip junction temperature, T
where:
The thermal resistance values used are based on the JEDEC JESD51 series of standards to provide consistent values for
estimations and comparisons. The difference between the values determined for the single-layer (1s) board compared to a
four-layer board that has two signal layers, a power and a ground plane (2s2p), demonstrate that the effective thermal resistance
is not a constant. The thermal resistance depends on the:
Connect all the ground and power balls to the respective planes with one via per ball. Using fewer vias to connect the package
to the planes reduces the thermal performance. Thinner planes also reduce the thermal performance. When the clearance
between the vias leave the planes virtually disconnected, the thermal performance is also greatly reduced.
Freescale Semiconductor
•
•
•
•
T
R
P
Construction of the application board (number of planes)
Effective size of the board which cools the component
Quality of the thermal and electrical connections to the planes
Power dissipated by adjacent components
1
2
3
4
5
6
7
A
D
θJA
= ambient temperature for the package (
= power dissipation in the package (W)
Thermal characteristics are targets based on simulation that are subject to change per device
characterization.
Junction temperature is a function of die size, on-chip power dissipation, package thermal resistance,
mounting site (board) temperature, ambient temperature, air flow, power dissipation of other components
on the board, and board thermal resistance.
Per SEMI G38-87 and JEDEC JESD51-2 with the single-layer board horizontal.
Per JEDEC JESD51-6 with the board horizontal.
temperature is measured on the top surface of the board near the package.
Indicates the average thermal resistance between the die and the case top surface as measured by the
cold plate method (MIL SPEC-883 Method 1012.1) with the cold plate temperature used for the case
temperature.
Thermal characterization parameter indicating the temperature difference between package top and the
junction temperature per JEDEC JESD51-2. When Greek letters are not available, the thermal
characterization parameter is written as Psi-JT.
Thermal resistance between the die and the printed circuit board per JEDEC JESD51-8. Board
R
General Notes for Specifications at Maximum Junction Temperature
= junction-to-ambient thermal resistance (
R
R
Ψ
θJMA
Symbol
θJB
θJC
JT
Table 8. Thermal Characteristics for 208-pin MAPBGA
CC
CC
CC
CC
Junction-to-ambient
Junction-to-board
Junction-to-case
Junction-to-package top natural
convection
Preliminary—Subject to Change Without Notice
MPC5634M Microcontroller Data Sheet, Rev. 3
7
Parameter
T
6
J
J
5
, can be obtained from the equation:
= T
2,4
o
C)
A
+ (R
o
C/W)
θJA
* P
D
)
@200 ft./min., four
Four layer board -
layer board 2s2p
Conditions
2s2p
1
(continued)
Electrical Characteristics
Value
20
13
6
2
°C/W
°C/W
°C/W
°C/W
Unit
Eqn. 1
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